With the increase in the penetration rate of renewable energy, to improve the reliability and resilience of the grid, a two-stage operation strategy for the transmission grid considering the uncertainty island and network reconfiguration is proposed in this paper. Considering the economy and reliability at the same time, in normal operation, it can promote the consumption of renewable energy through unit combination. When the system enters the isolated island state, the network structure can be changed to maximize the continuous power supply time of the important loads of the system under the isolated island state. Finally, the actual system is used for simulation verification to prove the validity of the model established in this paper.